The purpose of this proposal is to complete the organization of a Medical Flora of South America and to publish it in two volumes. The volumes will include a telescoped text of South American plants incorporating a large and nearly completed ethnomedicinal database at Washington University with the NAPRALERT files on ethnomedicine, chemistry, and pharmacology housed at the College of Pharmacy, University of Illinois/Chicago. This immense synthesis by species of about 8,500 ethnomedicinal plant records from herbaria and selectively from the literature with about 20% of the entire NAPRALERT database will provide researchers and others a major reference to perhaps the richest vegetational area in the world. Volumes will be fully referenced, indexed in several ways to show plant inter-relations, for example, and in sufficient textual detail to allow researchers to examine what is known medically, chemically, and biologically about these plants. Moreover, the authors (Walter H. Lewis, Norman R. Farnsworth, Marvin H. Malone, and Memory P. Elvin-Lewis), besides editing specific sections of each plant family treatment, will provide a brief summary of each family to (1) highlight plants of greatest promise based on their repetitive use for the same medicinal purpose by different peoples in South America, which is one indication of the existence of both biologically active compounds and therapeutic values; (2) summarize important biodynamic compounds, particularly in relation to biological activities; and (3) suggest research areas of greatest promise. This summary thus provides a selective guide family by family to plants and their natural products which have the potential to contribute to an enriched pharmacopeia of major benefit to mankind.